A few years ago I started to have some electrical issues with but it in no way was related to the battery even though that's exactly what I thought it was at first. So I read and read reviews and test and opinions but so many seamed suspect with little experience or long term results. Many just read what the manufacturer says for what every they are talking about. Which is why I through it must be my batteries and it needs to be replaced. Only recently, 2023, does it seem that finally the 10.5V AGM = Replace has finally been called out as just BS but articles from 2019 or earlier all tend to repeat that claim.

Most relevant to my was that AGM batteries when discharged should always use an AGM charger. But a completely dead (just a few volts) AGM is perfectly fine if it just slowly discharged overtime. AGM charges won't charge in this situation which is what was happening to me, why they won't I don't know but I'd guess because for some safety reason they don't want to charge a battery they might be damaged rather then just discharged. Trick it to hook a good battery and charger in parallel with the dead and it will take many hours but you'll have two good charged batteries in the end.


Anyway my issue it turned out to be a combination of things but primarily a poor ground strap preventing the battery from being charged fully (essentially a resistor in series), with secondary factors such as cold weather and many days between trips long enough to recharge the battery. Now with a new ground strap and a disconnect on the battery I can leave it for weeks with no issues in below freezing weather. It was a costly lesson because I replaced two batteries that were probably just fine when the problem was just 30 dollar part and a 20 dollar switch. Unfortunately I do not have access to an outlet in my parking garage for a battery tender.